an overview of the brain
The brain is one of the largest and one of the most complex organs in our human body. Together with the spinal cord, it makes up the central nervous system. Compared to an animal’s brain, the human brain has the same structure, but it differs in size.
before dissection
To start the demonstration, the brain will be rinsed first through cold running water to remove the blood. Then, a disinfectant solution in a container will be used for the instruments to be placed after the dissection to reduce the number of microorganisms and prevent risk to the patient.
Make sure to use Personal Protective Equipment namely: lab gown, laboratory gloves, and safety glasses. Materials to be used are Dissecting kit, Dissecting pan, Plastic cover or newspaper, and Washcloth or paper towel. Now, we can start the dissection.
during dissection
Carefully place the brain on the dissecting board flat side down so the white spinal cord at one end rests on the board. The attached arteries are the blood vessels in the brain. The dura mater of the brain is no longer attached but the doctor observes that the pia mater is still on the brain. The pia mater is the innermost meninges that protect the brain and spinal cord.
Use forceps to gently peel away and remove the layers of the membrane. This is the left hemisphere and right hemisphere of the brain. The medical intern opens the brain in the midsagittal section. The doctor locates the cerebrum of the brain. Posterior to the cerebrum is the cerebellum. Inferior to the cerebrum are the pons, medulla, and spinal cord.
For the next part of the dissection, locate the olfactory bulb. It is in the inferior side of the brain and lies below the frontal lobe of the cerebrum and optic chiasma. We can observe that the brain consists of many ridges and intervening grooves. These ridges and grooves serve to separate brain regions and increase cognitive ability. While the medial longitudinal fissure divides the cerebrum into left and right hemispheres
Each cerebral hemisphere is divided into 4 lobes. The first lobe is the frontal lobe, the second is the parietal lobe, the third lobe is the temporal lobe, and the last one is the occipital lobe. At the back of the brain, attached to the brain stem, and below the occipital lobe is the cerebellum. It is folded and incompletely divided by a medial part called the vermis.
Use a scalpel to carefully slice through the brain along the centerline (longitudinal fissure),
starting at the cerebrum, and down through the cerebellum and brain stem. Separate the two hemispheres of the brain. There are 2 hemispheres in the brain. The left hemisphere and the right hemisphere. With the cut side facing up we will locate the following: the corpus callosum, third and fourth ventricles, thalamus, hypothalamus, pineal body, pituitary gland, pons, and medulla.
Now, we will identify the grey and white matter. The white matter is an area in the nervous system that is mainly made up of myelinated axons. White matter plays an essential role in communication within the brain and between the brain and spinal cord
after dissection
After dissecting, all parts of the pig’s brain, as well as the gloves, must be wrapped in a newspaper and placed in a plastic garbage bag. After collecting all waste materials, double its bag for disposal. Then for the dissecting board and instruments, immediately soak it in a disinfectant solution or in hot soapy water, then rinse. Make sure that all instruments are cleaned then dry all equipment thoroughly to avoid rusting. Then, place all the equipment used to its original places and disinfect your workplace and wash hands thoroughly